MDRAO Decontamination Processes and Equipment 2 — Questions and Answers
Question 1: Which type of washer-disinfector cycle uses a thermal disinfection phase to achieve an A0 value of at least 600?
- Ultrasonic cycle
- Thermal-chemical cycle
- Thermal disinfection cycle (Correct answer)
- Pre-rinse only cycle
Correct answer: Thermal disinfection cycle
A thermal disinfection cycle achieves an A0 value of at least 600, indicating sufficient lethal heat exposure to disinfect instruments.
Question 2: What is the primary purpose of the enzymatic pre-soak step in instrument decontamination?
- To sterilize instruments before washing
- To break down protein-based bioburden for easier removal (Correct answer)
- To neutralize chemical disinfectants
- To remove rust and mineral deposits
Correct answer: To break down protein-based bioburden for easier removal
Enzymatic pre-soaks break down proteins, fats, and carbohydrates in bioburden, making them easier to remove during the wash cycle.
Question 3: A technician notices white mineral deposits on instruments after automated washing. What is the most likely cause?
- Inadequate detergent concentration
- Hard water or insufficient final rinse temperature (Correct answer)
- Overloading the washer rack
- Expired enzymatic detergent
Correct answer: Hard water or insufficient final rinse temperature
Hard water contains calcium and magnesium salts that precipitate as white deposits, especially if the final rinse does not use softened or purified water.
Question 4: When loading a washer-disinfector, instruments with box locks should be positioned in what manner?
- Fully closed to prevent damage
- Open to allow water and detergent to reach all surfaces (Correct answer)
- Stacked to maximize load capacity
- Tip-down to improve drainage
Correct answer: Open to allow water and detergent to reach all surfaces
Box locks must be open during washing so water and detergent can penetrate the joint and remove bioburden from all surfaces.
Question 5: Which chemical agent is most appropriate for high-level disinfection of heat-sensitive flexible endoscopes?
- Isopropyl alcohol 70%
- Glutaraldehyde 2% or OPA 0.55% (Correct answer)
- Sodium hypochlorite 10%
- Quaternary ammonium compound
Correct answer: Glutaraldehyde 2% or OPA 0.55%
Glutaraldehyde 2% and OPA 0.55% are approved high-level disinfectants for heat-sensitive scopes, achieving elimination of all microorganisms except high numbers of spores.
Question 6: What does the term 'cavitation' refer to in the context of ultrasonic cleaning?
- The formation and implosion of microscopic bubbles that dislodge soil (Correct answer)
- The vibration of cleaning brushes against instrument surfaces
- The heating of water to remove bioburden
- The chemical breakdown of detergents
Correct answer: The formation and implosion of microscopic bubbles that dislodge soil
Cavitation is the rapid formation and violent collapse of microscopic bubbles created by high-frequency sound waves, which mechanically dislodge soil from instrument surfaces.
Question 7: Which personal protective equipment (PPE) is mandatory when working in the decontamination area handling contaminated instruments?
- Surgical gown and sterile gloves only
- Impermeable gown, utility gloves, face shield, and closed-toe shoes (Correct answer)
- N95 respirator and latex exam gloves
- Sterile drape and hair cover only
Correct answer: Impermeable gown, utility gloves, face shield, and closed-toe shoes
The decontamination area requires an impermeable gown, heavy-duty utility gloves, face shield or goggles, and closed-toe/slip-resistant shoes to protect against splashes and sharps.
MDRAO Decontamination Processes and Equipment 2
Which type of washer-disinfector cycle uses a thermal disinfection phase to achieve an A0 value of at least 600?